Fix cross compilation of LLVM-3.9 #25218
Conversation
It's now possible to cross compile llvm:
`nix-build -E '(import ./. { crossSystem = import ./platform.nix; }).pkgs.llvm'`
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@expipiplus1, thanks for your PR! By analyzing the history of the files in this pull request, we identified @gebner, @vcunat and @copumpkin to be potential reviewers. |
expipiplus1
changed the title
| @@ -39,7 +42,13 @@ in stdenv.mkDerivation rec { | |||
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| outputs = [ "out" ] ++ stdenv.lib.optional enableSharedLibraries "lib"; | |||
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| buildInputs = [ perl groff cmake libxml2 python libffi ] | |||
| buildInputs = [ | |||
| buildPackages.perl | |||
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Can these be nativeBuildInputs? might not even cause rebuild for native due to some normalizing in stdenv.
| @@ -13,7 +13,7 @@ let | |||
| mv clang-tools-extra-* $sourceRoot/tools/extra | |||
| ''; | |||
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| buildInputs = [ cmake libedit libxml2 llvm python ]; | |||
| buildInputs = [ buildPackages.cmake libedit libxml2 llvm python ]; | |||
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cmake should also be a nativeBuildInput. Note that buildPackages. is not necessary in this case because mkDerivation will magically fish it out.
| @@ -88,6 +97,9 @@ in stdenv.mkDerivation rec { | |||
| ++ stdenv.lib.optionals (isDarwin) [ | |||
| "-DLLVM_ENABLE_LIBCXX=ON" | |||
| "-DCAN_TARGET_i386=false" | |||
| ] ++ stdenv.lib.optionals (buildPlatform != hostPlatform) [ | |||
| "-DCMAKE_CROSSCOMPILING=True" | |||
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Hmm, this is a general cmake thing? This could be generalized to be so added for all derivations with cmakeFlags I suppose.
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This error was cause by multiple-outputs.sh not setting NIX_CROSS_LDFLAGS
| buildInputs = [ | ||
| groff | ||
| libxml2 | ||
| libffi ] |
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Not to be a big nit, but ] on the line below before ++ I think would be more idiomatic.
The current cc-wrapper script seems to have trouble setting the rpath correctly. Hopefully NixOS#25047 will fix this.
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@expipiplus1 do you consider this ready to merge? Given LLVM 3.9 is what Mesa currently uses, I would target this to |
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It's not entirely clear to me this is/need-be a hash-breaking change given the way *inputs are normalized. It does look good to me, so definitely want to merge somewhere. |
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I think the order of inputs needs to change (because the current situation means interleaving of native and target inputs), and that's a hash change. |
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@7c6f434c Yeah, I think it's good to go. I'd like to get to the bottom of why the shared library support doesn't work at some time. |
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I'm in no hurry though! |
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Well, I guess when you want it merged you want to retarget it to the |
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done! |
Although LLVM now cross compiles successfully the executable do not run, the
RUNPATHof the resultant executables in incorrect, it does not contain theLLVM lib output.